Having tried most all ways of doing this I have a couple of suggestions. Obviously breaking up the dirt produces the best plots especially if you are planting something like tubers or brassicas. Best advice is to spray first and kill whatever is there. Saves a lot of headaches. If you try a drag harrow next recognize the drag will gather all that dead matter into piles which require constant removal and clearing of the drag before you ever get to touch dirt. The drag will literally ride on top of the piles if they aren't cleared. Takes a lot of passes. And a lot more if you don't kill the vegetation first. A disc and tractor work great except again takes a lot of passes to slice up even dead matter and reach dirt. Disc's require A LOT of weight to be effective. They work great in soft soil. But we don't have that in NY, we have a lot of clay. Hard unworked dirt requires a lot of passes. Lastly, I finally stumbled on a Land Pride SF series Scarifier. Best investment ever. Solved all my problems mentioned above. I have a bigger tractor so I attach my disc behind the scarifier and I can turn dirt in the first pass even over sod. The scarifier biting in provides down pressure to the disc. With an 8n you would probably have to run these separately but it will work. Same with your Mahindra. Good luck. Let us know how it goes.